U.S. patent application number 14/558526 was filed with the patent office on 2016-02-18 for method of and system for generating virtual engine sound.
The applicant listed for this patent is HYUNDAI MOTOR COMPANY. Invention is credited to Ki Woong JEONG, Eun Soo JO, Seong Hyeon KIM, Dong Chul PARK.
Application Number | 20160046234 14/558526 |
Document ID | / |
Family ID | 55235023 |
Filed Date | 2016-02-18 |
United States Patent
Application |
20160046234 |
Kind Code |
A1 |
KIM; Seong Hyeon ; et
al. |
February 18, 2016 |
METHOD OF AND SYSTEM FOR GENERATING VIRTUAL ENGINE SOUND
Abstract
A method for generating a virtual engine sound and a virtual
engine sound generating system using the same involve determining a
basic waveform of a virtual engine sound based on engine variables
including an engine RPM, primarily correcting a basic level of the
basic waveform based on environmental variables to determine a
primarily corrected waveform, secondarily correcting the primarily
corrected waveform based on reaction variables to determine a final
waveform, and generating a virtual engine sound having the final
waveform through a sound generation device.
Inventors: |
KIM; Seong Hyeon;
(Anyang-si, KR) ; PARK; Dong Chul; (Anyang-si,
KR) ; JO; Eun Soo; (Hwaseong-si, KR) ; JEONG;
Ki Woong; (Hwaseong-si, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HYUNDAI MOTOR COMPANY |
Seoul |
|
KR |
|
|
Family ID: |
55235023 |
Appl. No.: |
14/558526 |
Filed: |
December 2, 2014 |
Current U.S.
Class: |
381/86 |
Current CPC
Class: |
B60Q 5/00 20130101; G10K
15/02 20130101 |
International
Class: |
B60Q 5/00 20060101
B60Q005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 18, 2014 |
KR |
10-2014-0106921 |
Claims
1. A method for generating a virtual engine sound, comprising:
determining a basic waveform of a virtual engine sound based on
engine variables including an engine RPM; primarily correcting a
basic level of the basic waveform based on environmental variables
to determine a primarily corrected waveform; secondarily correcting
the primarily corrected waveform based on reaction variables to
determine a final waveform; and generating a virtual engine sound
having the final waveform through a sound generating component.
2. The method of claim 1, wherein the engine variables further
include a phase angle of a crankshaft, and the basic waveform is a
waveform time synchronized with a waveform of an actual engine
sound.
3. The method of claim 2, wherein the basic waveform is expressed
as L.times.sin(.omega.t+O), where, L denotes the basic level
determined based on present engine RPM, .omega. denotes angular
frequency determined based on frequency of the present engine RPM,
and O denotes a phase angle delay value determined based on phase
angle of the crankshaft.
4. The method of claim 1, wherein the environmental variables
include at least one of a coolant temperature of an engine, an
intake temperature, an engine oil temperature and a transmission
oil temperature.
5. The method of claim 1, wherein the reaction variables include at
least one of a position of an accelerator pedal, an engine torque
and a vehicle speed.
6. The method of claim 1, wherein, in the primarily correcting of
the basic level of the basic waveform, a corrected level of the
primarily corrected waveform is determined by multiplying an
environmental correction coefficient set according to environmental
variables to a basic level.
7. The method of claim 6, wherein the environmental correction
coefficient is set as a value varied with engine RPM.
8. The method of claim 1, wherein, in the secondarily correcting of
the primarily corrected waveform, a final level of the final
waveform is determined by applying a correction curve set based on
the reaction variables to a corrected level of the primarily
corrected waveform.
9. A method for generating a virtual engine sound comprising:
determining a basic waveform of a virtual engine sound based on
engine variables including an engine RPM; primarily correcting a
basic level of the basic waveform based on reaction variables to
determine a primarily corrected waveform; secondarily correcting
the primarily corrected waveform based on environmental variables
to determine a final waveform; and generating a virtual engine
sound having the final waveform through a sound reproduction
device.
10. The method of claim 9, wherein the engine variable further
includes a phase angle of a crankshaft, and the basic waveform is a
waveform time synchronized with a waveform of an actual engine
sound.
11. The method of claim 10, wherein the basic waveform is expressed
as L.times.sin(.omega.t+O), where, L denotes the basic level
determined based on present engine RPM, .omega. denotes an angular
frequency determined based on a frequency of the present engine
RPM, and O denotes a phase angle delay value determined based on
phase angle of the crankshaft.
12. The method of claim 9, wherein the environmental variables
include at least one of a coolant temperature of an engine, an
intake temperature, an engine oil temperature and a transmission
oil temperature.
13. The method of claim 9, wherein the reaction variables include
at least one of a position of an accelerator pedal, an engine
torque and a vehicle speed.
14. The method of claim 9, wherein, in the primarily correcting of
the basic level of the basic waveform, a corrected level of the
primarily corrected waveform is determined by applying a correction
curve set based on the reaction variables to the basic level.
15. The method of claim 9, wherein, in the secondarily correcting
of the primarily corrected waveform, a final level of the final
waveform is determined by multiplying an environmental correction
coefficient set according to the environmental variables to a
corrected level of the primarily corrected waveform.
16. The method of claim 15, wherein the environmental correction
coefficient is set as a value varied with the engine RPM.
17. A virtual engine sound generating system comprising: a data
detector for detecting engine variables, environmental variables
and reaction variables; a controller for determining a waveform of
the virtual engine sound based on the engine variables, the
environmental variables and the reaction variables; and a sound
reproduction device for generating the virtual engine sound under
control of the controller, wherein the engine variables include an
engine RPM, the environmental variables include at least one of a
coolant temperature of an engine, an intake temperature, an engine
oil temperature and a transmission oil temperature, and the
controller determines a basic waveform of the virtual engine sound
based on the engine variables, corrects a basic level of the basic
waveform based on the environmental variables and the reaction
variables to determine a final waveform.
18. The system of claim 17, wherein the engine variables further
include a phase angle of a crankshaft, the reaction variables
include at least one of a position of an accelerator pedal, an
engine torque and a vehicle speed, and the basic waveform is a
waveform time synchronized with a waveform of an actual engine
sound.
19. The system of claim 17, wherein the controller is configured to
primarily correct the basic level of the basic waveform based on
the environmental variables to determine a primarily corrected
waveform, and secondarily correct the primarily corrected waveform
based on the reaction variables to determine the final
waveform.
20. The system of claim 17, wherein the controller is configured to
primarily correct the basic level of the basic waveform based on
the reaction variables to determine a primarily corrected waveform,
and secondarily correct the primarily corrected waveform based on
the environmental variables to determine the final waveform.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and benefit of the
Korean Patent Application No. 10-2014-0106921 filed in the Korean
Intellectual Property Office on Aug. 18, 2014, the entire contents
of which are incorporated herein by reference.
BACKGROUND OF THE DISCLOSURE
[0002] (a) Field
[0003] The disclosure herein relates to a method for generating a
virtual engine sound and to a virtual engine sound generating
system using the same. More particularly, the disclosure relates to
a method for generating a virtual engine sound for generating a
virtual engine sound which is time synchronized with a waveform of
an actual engine sound and is robust to an environmental change;
and a virtual engine sound generating system using the same.
[0004] (b) Description of the Related Art
[0005] In order to change the tone of an actual engine sound which
is generated as an engine is operated, an ASD (Active Sound Design)
method is under research. By overlapping the virtual engine sound
on the actual engine sound, a sensory quality related to the engine
sound may be improved.
[0006] A related art process for generating the virtual engine
sound will be described, with reference to FIG. 3.
[0007] FIG. 3 illustrates a graph for describing a related art
process for generating the virtual engine sound.
[0008] Referring to FIG. 3, a controller has an actual engine sound
line which varies with an engine RPM stored therein. The actual
engine sound line varied with the engine RPM may be set in advance
with an experiment taking a specification of the engine into
account. The controller has a target engine sound line in which
sound volume increases according to the engine RPM stored therein.
The target engine sound line may be preset to a value a person of
an ordinary skill in the art may determine to be desirable.
Alternatively, the target engine sound line may be set to a value
the user desires. The controller determines the sound volume of the
virtual engine sound matched to the virtual engine sound line for
generating the same.
[0009] However, in a particular engine RPM state, if the waveform
of the actual engine sound having a frequency at the particular
engine RPM is not time synchronized with the waveform of the
virtual engine sound having that frequency, a problem may be
caused, in which the sound volume matched to the target engine
sound line fails to output due to destructive interference and
constructive interference.
[0010] Moreover, the sound volume of the actual engine sound varies
with environmental changes, such as temperature, duration of use
and degradation of the vehicle. However, since the actual engine
sound line is preset by experiment at room temperature (For an
example, 20.degree. C.), a problem may be caused, in which the
sound volume matched to the target engine sound line fails to
output.
[0011] The above information disclosed in this Background section
is only for enhancement of understanding of the background of the
invention and therefore it may contain information that does not
form the prior art that is already known in this country to a
person of ordinary skill in the art.
SUMMARY OF THE DISCLOSURE
[0012] The present disclosure has been made in an effort to
describe a method for generating a virtual engine sound, and a
virtual engine sound generating system using the same, having
advantages of generating a virtual engine sound which is time
synchronized with a waveform of an actual engine sound, and is
robust to environmental change.
[0013] Accordingly, an object of the present invention is to
provide a method for generating a virtual engine sound for
generating a virtual engine sound which is time synchronized with a
waveform of an actual engine sound and is robust to environmental
change; and a virtual engine sound generating system using the
same.
[0014] According to an exemplary embodiment of the present
invention, a method for generating a virtual engine sound includes
determining a basic waveform of a virtual engine sound based on
engine variables including engine RPM, primarily correcting a basic
level of the basic waveform based on environmental variables to
determine a primarily corrected waveform, secondarily correcting
the primarily corrected waveform based on reaction variables to
determine a final waveform, and generating a virtual engine sound
having the final waveform through a speaker or other sound
generating device.
[0015] The engine variables may further include phase angle of a
crankshaft, and the basic waveform may be a waveform time
synchronized with a waveform of an actual engine sound.
[0016] The basic waveform may be expressed as
L.times.sin(.omega.t+O), where, L denotes the basic level
determined based on the present engine RPM, .omega. denotes an
angular frequency determined based on a frequency of the present
engine RPM, and O denotes a phase angle delay value determined
based on the phase angle of the crankshaft.
[0017] The environmental variables may include at least one of
coolant temperature of an engine, intake temperature, engine oil
temperature and transmission oil temperature.
[0018] The reaction variables may include at least one of the
position of an accelerator pedal, engine torque and vehicle
speed.
[0019] In the primarily correcting of the basic level of the basic
waveform, a correction level of the primarily corrected waveform
may be determined by multiplying an environmental correction
coefficient set according to the environmental variables to the
basic level.
[0020] The environmental correction coefficient may be set as a
value varied with the engine RPM.
[0021] In the secondarily correcting of the primarily corrected
waveform, a final level of the final waveform may be determined by
applying a correction curve set based on the reaction variables to
a corrected level of the primarily corrected waveform.
[0022] According to an exemplary embodiment of the present
invention, a method for generating a virtual engine sound may
include determining a basic waveform of a virtual engine sound
based on engine variables including engine RPM, primarily
correcting a basic level of the basic waveform based on reaction
variables to determine a primarily corrected waveform, secondarily
correcting the primarily corrected waveform based on environmental
variables to determine a final waveform, and generating a virtual
engine sound having the final waveform through a speaker or other
sound generating device.
[0023] The engine variables may further include phase angle of a
crankshaft, and the basic waveform may be a waveform time
synchronized with a waveform of an actual engine sound.
[0024] The basic waveform may be expressed L.times.sin(.omega.t+O),
where, L denotes the basic level determined based on the present
engine RPM, .omega. denotes an angular frequency determined based
on frequency of the present engine RPM, and O denotes a phase angle
delay value determined based on the phase angle of the
crankshaft.
[0025] The environmental variables may include at least one of a
coolant temperature of an engine, an intake temperature, an engine
oil temperature and a transmission oil temperature.
[0026] The reaction variables may include at least one of the
position of an accelerator pedal, engine torque and vehicle
speed.
[0027] In the primarily correcting of the basic level of the basic
waveform, a corrected level of the primarily corrected waveform may
be determined by applying a correction curve set based on the
reaction variables to the basic level.
[0028] In the secondarily correcting of the primarily corrected
waveform, a final level of the final waveform may be determined by
multiplying an environmental correction coefficient set according
to the environmental variables to a corrected level of the
primarily corrected waveform.
[0029] The environmental correction coefficient may be set as a
value varied with the engine RPM.
[0030] According to an exemplary embodiment of the present
invention, a virtual engine sound generating system may include a
data detector for detecting engine variables, environmental
variables and reaction variables, a controller for determining a
waveform of the virtual engine sound based on the engine variables,
the environmental variables and the reaction variables, and a
speaker or other sound generating device for generating the virtual
engine sound under control of the controller, wherein the engine
variables may include an engine RPM, the environmental variables
may include at least one of a coolant temperature of an engine, an
intake temperature, an engine oil temperature and a transmission
oil temperature, and the controller may determine a basic waveform
of the virtual engine sound based on the engine variables, may
correct a basic level of the basic waveform based on the
environmental variables and the reaction variables to determine a
final waveform.
[0031] The engine variables may further include phase angle of a
crankshaft, the reaction variables may include at least one of the
position of an accelerator pedal, engine torque and vehicle speed,
and the basic waveform may be a waveform time synchronized with a
waveform of an actual engine sound.
[0032] The controller may primarily correct the basic level of the
basic waveform based on the environmental variables to determine a
primarily corrected waveform, and may secondarily correct the
primarily corrected waveform based on reaction variables to
determine the final waveform.
[0033] The controller may primarily correct the basic level of the
basic waveform based on reaction variables to determine a primarily
corrected waveform, and may secondarily correct the primarily
corrected waveform based on the environmental variables to
determine the final waveform.
[0034] Thus, according to an exemplary embodiment of the present
invention, the waveform of the virtual engine sound can be time
synchronized with the waveform of the actual engine sound. And,
generation of the virtual engine sound taking environmental
variables into account permits generation of a virtual engine sound
that is robust to environmental change.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 illustrates a block diagram of a virtual engine sound
generating system in accordance with an exemplary embodiment of the
present invention.
[0036] FIG. 2 illustrates a flow chart showing the steps of a
method for generating a virtual engine sound in accordance with an
exemplary embodiment of the present invention.
[0037] FIG. 3 illustrates a graph for describing a related art
process for generating the virtual engine sound.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0038] The present invention will be described more fully
hereinafter with reference to the accompanying drawings, in which
an exemplary embodiment of the invention is shown. However, the
present invention is not limited to the exemplary embodiment
described herein, but may be embodied in other modes.
[0039] In order to describe the present invention clearly, portions
of the description not relevant to the description are omitted, and
throughout the specification, identical or similar elements will be
given the same reference numbers.
[0040] And, elements shown in the drawings are shown at will for
convenience of description, and the present invention is not
limited to the drawings.
[0041] In addition, throughout the specification, unless explicitly
described to the contrary, the word "comprise" and variations such
as "comprises" or to "comprising", will be understood to imply the
inclusion of stated elements but not the exclusion of any other
elements.
[0042] FIG. 1 illustrates a block diagram of a virtual engine sound
generating system in accordance with an exemplary embodiment of the
present invention.
[0043] Referring to FIG. 1, the virtual engine sound generating
system 100 includes a data detector 10, a controller 20, and a
speaker or other sound generating device 30.
[0044] The data detector 10 detects data for generating the virtual
engine sound, and the data detected by the data detector 10 is
transmitted to the controller 20. The data detector 10 may include
an engine RPM detector 11, a crank angle detector 12, a coolant
temperature detector 13, an intake temperature detector 14, a first
oil temperature detector 15, a second oil temperature detector 16,
an accelerator pedal position detector 17, an engine torque
detector 18 and a vehicle speed detector 19.
[0045] The engine RPM detector 11 is mounted at an output shaft of
the engine. The engine RPM detector 11 detects RPM of the engine
and transmits a signal corresponding thereto to the controller
20.
[0046] The crank angle detector 12 detects a phase angle of the
crankshaft and transmits a signal corresponding thereto to the
controller 20. Instead of the crank angle detector 12, a cam angle
detector may be used. Accordingly, in the specification and the
claims presented herein, it is to be understood that the crank
angle detector 12 includes the cam angle detector, and the phase
angle of the crank shaft includes the phase angle of the
camshaft.
[0047] The coolant temperature detector 13 detects a coolant
temperature of the engine and transmits a signal corresponding
thereto to the controller 20.
[0048] The intake temperature detector 14 detects an intake
temperature and transmits a signal corresponding thereto to the
controller 20.
[0049] The first oil temperature detector 15 detects the
temperature of oil used in the engine and transmits a signal
corresponding thereto to the controller 20.
[0050] The second oil temperature detector 16 detects the
temperature of oil used in a transmission and also transmits a
signal corresponding thereto to the controller 20.
[0051] The accelerator pedal position detector 17 detects the
position of an accelerator pedal (pressed degree of the accelerator
pedal) and transmits a signal corresponding thereto to the
controller 20. If the accelerator pedal is pressed fully, the
position of the accelerator pedal is 100%, and if the accelerator
pedal is not pressed, the position of the accelerator pedal is 0%.
Instead of the accelerator pedal position detector 17, a throttle
valve opening detector of a throttle valve mounted to an intake
passage may be used. Accordingly, in the specification and the
claims herein, it is to be understood that the accelerator pedal
position detector 17 includes the throttle valve opening detector,
and the position of the accelerator pedal includes the opening of
the throttle valve.
[0052] The engine torque detector 18 detects engine torque. The
engine torque may be detected by a sensor, or may be calculated by
using engine control variables, such as engine RPM, position of the
accelerator pedal, vehicle speed, fuel injection rate, and so
on.
[0053] The vehicle speed detector 19 detects vehicle speed and
transmits a signal corresponding thereto to the controller 20.
[0054] The controller 20 determines the phase of a waveform of the
virtual engine sound and level of the waveform corresponding to the
volume of the virtual engine sound based on the data detected by
the data detector 10. For the above purpose, the controller 20 may
be implemented with at least one microprocessor executed by a
predetermined program. The predetermined program may include a
series of commands for performing each step included in a method
for generating a virtual engine sound in accordance with an
exemplary embodiment of the present invention, to be described
later.
[0055] The controller 20 may include a memory for storing a sound
source of the virtual engine sound, a codec for converting a
digital sound source signal to an analog sound source signal and an
audio amplifier for amplifying the analog sound source signal from
the codec. Since the memory, the codec and the amplifier are
apparent to a person of an ordinary skill in the art, detailed
description thereof will be omitted.
[0056] The controller 20 generates the virtual engine sound with
the speaker or other device 30 mounted to a predetermined position
of the vehicle.
[0057] A method for generating a virtual engine sound in accordance
with an exemplary embodiment of the present invention will be
described with reference to FIG. 2, in detail.
[0058] FIG. 2 illustrates a flow chart showing the steps of a
method for generating a virtual engine sound in accordance with an
exemplary embodiment of the present invention.
[0059] Referring to FIG. 2, the method for generating a virtual
engine sound in accordance with an exemplary embodiment of the
present invention starts with detecting a data for generating a
virtual engine sound (S10). The data includes engine variables,
environmental variables and reaction variables.
[0060] That is, an engine RPM detector 11 may detect engine RPM,
crank angle detector 12 may detect a crankshaft phase angle, a
coolant temperature detector 13 may detect a coolant temperature of
the engine, intake temperature detector 14 may detect an intake
temperature, a first oil temperature detector 15 may detect an
engine oil temperature, a second oil temperature detector 16 may
detect a transmission oil temperature, accelerator pedal position
detector 17 may detect a position of an accelerator pedal, engine
torque detector 18 may detect an engine torque, and vehicle speed
detector 19 may detect vehicle speed.
[0061] If the data detector 10 detects and transmits the data to
the controller 20, the controller 20 determines a basic waveform of
the virtual engine sound based on the engine variables (S20). The
engine variables may include engine RPM and phase angle of the
crankshaft.
[0062] The basic waveform may be expressed as
L.times.sin(.omega.t+O). Where, L denotes a basic level determined
based on the present engine RPM, .omega. denotes an angular
frequency determined based on the frequency of the present engine
RPM, and O denotes a phase angle delay value determined based on
phase angle of the crankshaft. The controller 20 may store the
phase delay value that corresponds to the phase angle of the
crankshaft in a lookup table. However, if the basic waveform of the
virtual engine sound is determined based only on the engine RPM,
the basic waveform may be expressed as L.times.sin(.omega.t).
[0063] If the phase delay value is not taken into account, the
waveform of the virtual engine sound is not time synchronized with
the waveform of the actual engine sound, and destructive
interference and constructive interference take place. However, if
phase delay value is taken into account, the waveform of the
virtual engine sound time synchronized with the waveform of the
actual engine sound may be obtained.
[0064] The controller 20 primarily corrects the basic level (L)
based on the environment variables, to determine a primarily
corrected waveform (S30). The environmental variables may include
at least one of coolant temperature of the engine, intake
temperature, engine oil temperature and transmission oil
temperature. A corrected level of the primarily corrected waveform
may be determined by multiplying an environmental correction
coefficient (C) set according to the environmental variables to the
basic level (L). The controller 20 may store the environmental
correction coefficient (C) that corresponds to the environmental
variables in a lookup table form. Accordingly, the primarily
corrected waveform may be expressed as C.times.L=sin(.omega.t+O).
The environmental correction coefficient (C) may also be set as a
value varied with engine RPM. However, if the basic waveform of the
virtual engine sound is determined based only on the engine RPM,
the primarily corrected waveform may be expressed as
C.times.L.times.sin(.omega.t).
[0065] If the environmental variables are not taken into account,
the sound volume of the engine sound recognized by passengers will
vary with environmental change. However, if the environmental
variables are taken into account, a virtual engine sound robust
against environmental change may be obtained.
[0066] The controller 20 may secondarily correct the primarily
corrected waveform based on the reaction variables to determine a
final waveform (S40). The reaction variable may include at least
one of the position of the accelerator pedal, engine torque and
vehicle speed. The reaction variable may be a single variable which
is one of the position of the accelerator pedal, engine torque and
vehicle speed or a composite variable which is a combination of two
or more of the variables.
[0067] A final level of the final waveform may be determined by
applying a correction curve set based on the reaction variables to
a corrected level of the primarily corrected waveform. The
controller 20 may store the correction curve that corresponds to
the reaction variables in a lookup table. For example, if the
position of the accelerator pedal is low, the correction curve may
be set by a person of an ordinary skill in the art for generating
the virtual engine sound at a low sound volume.
[0068] The controller 20 generates a virtual engine sound having
the final waveform through the speaker or other sound generating
device 30 (S50). The final waveform is time synchronized with the
waveform of the actual engine sound and robust against
environmental change.
[0069] Although the specification illustrates that the controller
20 primarily corrects the basic level (L) based on environmental
variables to determine the primarily corrected waveform, and
secondarily corrects the primarily corrected waveform based on the
reaction variables to determine the final waveform, the present
invention is not so limited. That is, step S30 and the S40 may be
reversed in order. In this case, the controller 20 primarily
corrects the basic level (L) based on the reaction variables to
determine the primarily corrected waveform, and secondarily
corrects the primarily corrected waveform based on the
environmental variables to determine the final waveform. That is,
the corrected level of the primarily corrected waveform in step S30
may be determined by applying a predetermined correction curve
based on the reaction variables to the basic level (L) And, in step
S40, the final level of the final waveform may be determined by
multiplying an environmental correction coefficient (C) set
according to environmental variables to the correction level of the
primarily corrected waveform.
[0070] Thus, according to an exemplary embodiment of the present
invention, the waveform of the virtual engine sound may be time
synchronized with the waveform of the actual engine sound, and by
generating the virtual engine sound taking the environmental
variables into account, a virtual engine sound can be generated,
which is robust against environmental change.
[0071] While this invention has been described in connection with
what is presently considered to be practical exemplary embodiments,
it is to be understood that the invention is not limited to the
disclosed embodiments, but, on the contrary, is intended to cover
various modifications and equivalent arrangements included within
the spirit and scope of the appended claims.
* * * * *